Miller joined Celtic's youth system in 1997 and made his professional debut with the club during the 1999-2000 season. He signed with Manchester United on a free transfer in 2004 and went on to make 22 appearances for the English giants across two terms at Old Trafford.

The Cork, Ireland native also made stops with Sunderland, Queens Park Rangers, Hibernian, Perth Glory, Brisbane Roar, Melbourne City, Cork City and Wilmington FC as well as loan stints with AGF Aarhus and Leeds United during a successful journeyman career that spanned 17 years.

He was part of the Republic of Ireland team that won the under-16 European championship in 1998. Later, he collected 21 caps for the senior team between 2004 and 2009, scoring one goal in a win over Sweden in 2006.

Belfast Live's Chris Sherrard provided a statement from a Cork Schoolboys League spokesperson about Miller's death:

"We have received the very sad news that Liam Miller has passed away tonight. The thoughts and prayers of everyone in the CSL are with Liam's family tonight. A minutes silence will be observed in all CSL games this weekend in Liam's memory. May he rest in peace."